JP2017108795A - Biological signal detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biological signal detector capable of being stably mounted on the neck of a user irrespective of the thickness of the neck of the user without providing a mechanism to adjust the length of a neck band.SOLUTION: A blood pressure variation estimation device 4 (a biological signal detector 1) includes a neck band 13 that can be mounted along a circumferential direction of the neck of a user, sensor parts 11 and 12 attached to the neck band 13 for detecting a biological signal, and a support member 16, both ends of which are connected to an inner side surface of the neck band 13. The neck band 13 is formed roughly into a C-shape, and is energized in a direction that both ends get closer to each other. The support member 16 is flexible, and is deformed in an arc shape by the energizing force of the neck band 13 so that the deformation becomes larger as the interval between the two ends connected to the neck band 13 becomes shorter, and projects to the inside of the neck band 13 (in a neck direction when mounted).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a biological signal detection apparatus that detects a biological signal.

  In recent years, people's interest in health management, maintenance and promotion has increased. Therefore, it is desired that people can obtain biological information such as pulse and electrocardiogram more easily in daily life. Here, Patent Document 1 discloses a biological information detection apparatus that can be easily attached and detached and can detect biological information such as an electrocardiographic signal and blood oxygen saturation without restriction.

  This biological information detection device is provided with a neckband that can be worn along the back of the neck of a subject, and the neckband that comes into contact with the subject when the subject wears the neckband (for example, a cardiac potential signal). And a biological information detection unit for detecting. In addition, the biological information detection unit includes one indifferent electrode provided at the center of the neckband, two related electrodes provided at both ends of the neckband, and a measuring unit.

JP 2007-202939 A

  By the way, the thickness of the neck (neck) varies greatly between individuals. Therefore, depending on the thickness of the neck, the contact state of the indifferent electrode and the related electrode may become unstable (the close contact state changes), noise may be easily applied, or a biological signal may not be acquired. Therefore, in the above-described biological information detection apparatus, it is preferable that the neckband can be adapted to neck portions of various thicknesses by adjusting the length thereof by an adjustment mechanism (slide mechanism) or the like.

  However, when wiring for connecting a plurality of electrodes (indifferent electrodes, related electrodes) and measuring means is passed through the neckband, the adjustment mechanism (sliding mechanism) may adversely affect these wirings. It is required to expand and contract. As a result, the structure of the adjustment mechanism becomes complicated, which may increase the size and weight of the neckband. For this reason, it has been desired to fit the user's neck (maintaining good contact with the neck) without providing an adjusting mechanism for adjusting the length of the neckband.

  The present invention has been made to solve the above-described problems, and in the neckband type biological signal detection device, the thickness of the neck of the user is provided without a mechanism for adjusting the length of the neckband. It is an object of the present invention to provide a biological signal detection device that can be worn more stably by the user's neck.

  A biological signal detection device according to the present invention includes a neckband that can be worn along the circumferential direction of a user's neck, a sensor unit that is attached to the neckband and detects a biological signal, and both ends of the neckband are included in the neckband. A support member connected to the side surface, the neckband is formed in a substantially C shape, and both end portions are urged toward each other, and the support member is supported at both end portions of the neckband by the urging force of the neckband. The closer to each other, the more it protrudes to the inside of the neckband.

  According to the biological signal detection device of the present invention, the neckband is formed in a substantially C shape, and is biased in a direction in which both ends approach each other (that is, a direction in which the user's neck is sandwiched when worn). . In addition, the support member becomes closer to the inner side of the neck band (in the neck direction when worn) as the both ends of the neck band come closer to each other due to the urging force of the neck band. ). For this reason, the inner diameter of the neckband and the protruding amount of the support member are automatically (autonomously) adjusted according to the thickness of the neck of the user. As a result, a mechanism for adjusting the length of the neckband is not provided, and the user's neck is more stably worn regardless of the thickness of the user's neck (that is, between the sensor unit and the neck). It is possible to maintain a good contact state).

  In particular, in the biological signal detection apparatus according to the present invention, the support member has flexibility and is deformed as the distance between both ends connected to the neck band becomes shorter due to the biasing force of the neck band, and It is preferable to project in an arc shape to the inside of the neckband.

  In this case, the support member has flexibility, and is deformed as an interval between the both ends connected to the neckband (distance between the connection points) is shortened by an urging force of the neckband so that the support member has an arc shape. , It protrudes to the inside of the neckband (when worn, toward the neck). Therefore, a simpler, smaller and lighter mechanism can be stably attached to users with different neck thicknesses.

  Further, in the biological signal detection device according to the present invention, the support member has a plurality of connecting members that are swingably connected to each other, and the distance between both ends connected to the neckband by the biasing force of the neckband. It is preferable that the shorter the is, the larger the angle formed with the neckband is, and the more the angle is formed, and the inner side of the neckband is projected.

  In this case, the support member has a plurality of connecting members that are swingably connected to each other, and the distance between both ends connected to the neckband (distance between the connection points) is shortened by the urging force of the neckband. As it turns out, it swings so that the angle formed between it and the neckband increases, and protrudes to the inside of the neckband (in the neck direction when worn). Therefore, a simple, small, and lightweight mechanism can be stably attached to users with different neck thicknesses.

  In the biological signal detection device according to the present invention, the sensor unit is mounted so as to be swingable about the axial direction of the user's neck at the time of wearing and / or the neck front-rear direction perpendicular to the axial direction. Is preferred.

  In this case, the sensor unit is attached so as to be swingable about the axial direction of the user's neck at the time of wearing and / or the neck front-rear direction perpendicular to the axial direction. As described above, the sensor unit is attached so as to be swingable about the axial direction of the user's neck (that is, swingable in the circumferential direction of the neck), so that, for example, the neck portion is thickened at the time of wearing. Even if they are different, the sensor unit can be brought into close contact with the user's neck. In addition, for example, the contact surface can be held following a movement in which the neck is twisted. As a result, it is possible to maintain a good contact state between the sensor unit and the neck regardless of individual differences such as the thickness of the neck and the movement of the neck. In this case, the sensor unit is attached so as to be swingable about the neck front-rear direction perpendicular to the axial direction of the neck (that is, swingable in the axial direction of the neck). It is possible to hold the contact surface following the movement of the neck being tilted.

  Alternatively, in the biological signal detection device according to the present invention, it is preferable that the sensor unit is attached so as to be swingable about the short side direction and / or the long side direction of the neckband.

  In this case, the sensor unit is attached so as to be swingable about the short side direction and / or the long side direction of the neckband. As described above, the sensor unit is attached so as to be able to swing around the short direction of the neckband (that is, to be able to swing in the circumferential direction of the neck). Even if different, the sensor part can be brought into close contact with the user's neck. In addition, for example, the contact surface can be held following a movement in which the neck is twisted. As a result, it is possible to maintain a good contact state between the sensor unit and the neck regardless of individual differences such as the thickness of the neck and the movement of the neck. Further, in this case, the sensor unit is attached so as to be swingable about the longitudinal direction of the neckband (that is, swingable in the axial direction of the neck portion), so that, for example, the neck portion is tilted at the time of wearing. It is possible to hold the contact surface following the movement.

  In the biological signal detection device according to the present invention, it is preferable that the sensor unit is disposed on the inner surface of the neckband and / or the support member.

  In this case, the sensor unit is disposed on the inner surface of the neckband and / or the support member (the surface on the side that contacts the side surface of the neck when worn). Therefore, even if the thickness of the user's neck is different, the sensor can be stably brought into contact with the neck, and a biological signal can be detected (measured) stably.

  According to the present invention, in the neckband type biological signal detection device, a mechanism for adjusting the length of the neckband is not provided, and the neck of the user is more stable regardless of the thickness of the user's neck. It becomes possible to attach to.

It is a top view which shows the external appearance shape of the neckband type blood pressure fluctuation estimation apparatus using the biological signal detection apparatus which concerns on 1st Embodiment, (a) shows a shape when it mounts | wears with a thin neck, (b ) Is a diagram showing the shape when mounted on a thick neck. It is a perspective view which shows the external appearance (at the time of mounting | wearing) of the neckband type blood pressure fluctuation estimation apparatus using the biological signal detection apparatus which concerns on 1st Embodiment. It is a block diagram which shows the structure of the blood-pressure fluctuation | variation estimation apparatus using the biological signal detection apparatus which concerns on 1st Embodiment. It is a flowchart which shows the process sequence of the blood pressure fluctuation estimation process by the blood pressure fluctuation estimation apparatus using the biological signal detection apparatus which concerns on 1st Embodiment. It is a top view which shows the external appearance shape of the neckband type blood pressure fluctuation estimation apparatus using the biological signal detection apparatus which concerns on 2nd Embodiment, (a) shows a shape when it mounts | wears with a thin neck, (b ) Is a diagram showing the shape when mounted on a thick neck.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Moreover, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted. Here, a case where the biological signal detection device is applied to a blood pressure fluctuation estimation device will be described as an example.

(First embodiment)
First, the configuration of the blood pressure fluctuation estimation device 3 using the biological signal detection device 1 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a plan view showing an external shape of a neckband blood pressure fluctuation estimation device 3 using the biological signal detection device 1, and (a) shows a shape when worn on a thin neck, and (b) ) Is a diagram showing the shape when mounted on a thick neck. FIG. 2 is a perspective view showing an appearance (at the time of wearing) of the neckband blood pressure fluctuation estimation device 3 using the biological signal detection device 1. FIG. 3 is a block diagram illustrating a configuration of a blood pressure fluctuation estimation device 3 using the biological signal detection device 1.

  The blood pressure fluctuation estimation device 3 detects an electrocardiogram signal and a pulse wave signal, and detects a pulse from the time difference between the R wave peak of the detected electrocardiogram signal (cardiac radio wave) and the peak (rise point) of the pulse wave signal (pulse wave). The wave propagation time is measured, and the fluctuation of the blood pressure of the user is estimated based on the time series data of the measured pulse wave propagation time. In particular, the blood pressure fluctuation estimation device 3 has a function of continuously and more stably acquiring the pulse wave propagation time even when the posture of the user changes during measurement of the pulse wave propagation time. Yes. Further, the blood pressure fluctuation estimation device 3 detects and classifies the posture of the user, corrects the pulse wave propagation time based on the classification result, and based on the corrected time series data of the pulse wave propagation time, It has a function to estimate fluctuations.

  Therefore, the blood pressure fluctuation estimation device 3 mainly detects a pair of electrocardiographic electrodes 15 and 15 for detecting an electrocardiogram signal, a pulse wave sensor 20 for detecting a pulse wave signal, and a posture of the user. An acceleration sensor 22 and a signal processing unit 31 that measures and corrects the pulse wave propagation time from the detected electrocardiogram signal and pulse wave signal to estimate blood pressure fluctuations are provided.

  Here, in this embodiment, as shown in FIGS. 1 and 2, the blood pressure fluctuation estimation device 3 is a neckband type. For example, as shown in FIG. 2, the blood pressure fluctuation estimation device 3 acquires time-series data of pulse wave propagation time by wearing it on a user's neck (neck) and estimates blood pressure fluctuations. is there. The blood pressure fluctuation estimation device 3 includes a substantially C-shaped (or U-shaped) neckband 13 that is elastically mounted so as to sandwich the neck from the back side of the user's neck, and the neckband 13 at both ends. A support member 16 connected to the inner surface and abutting on the back of the user's neck at the time of wearing; and a sensor unit 11 that contacts both sides of the user's neck by being disposed at both ends of the neckband 13; 12 and a photoelectric pulse wave sensor (sensor unit) 20 that is disposed on the support member 16 and comes into contact with the vicinity of the back midline of the user's neck.

  The neckband 13 can be worn along the circumferential direction of the user's neck. That is, as shown in FIG. 2, the neckband 13 is formed in a substantially C shape (or U shape) and extends from one side of the user's neck to the other side of the user. It is worn along the back of the neck. More specifically, the neck band 13 includes, for example, a belt-shaped plate spring and a rubber coating that covers the periphery of the plate spring. Therefore, the neckband 13 has elasticity and is urged in a direction in which both ends approach each other (so that the width of the opening is narrowed, that is, in the direction of sandwiching the user's neck when worn). When the user wears the neckband 13, the neckband 13 is held in contact with the user's neck.

  In addition, it is preferable to use what has biocompatibility as rubber coating. Further, instead of the rubber coating, for example, a coating made of plastic can be used.

  The support member 16 is, for example, a member formed in a substantially band shape (or columnar shape) with rounded corners, and both ends thereof are connected to the inner side surface of the neckband 13. In particular, the support member 16 is formed of a material having flexibility (or elasticity) such as rubber, for example, and the urging force of the neck band 13 causes the both ends of the neck band 13 to approach each other (the degree of opening is reduced). As it gets smaller, it protrudes to the inside of the neckband 13 (that is, toward the neck when worn). Therefore, when mounted on the neck of the user, the support member 16 is elastically deformed by the urging force of the neckband 13 and protrudes (extrudes) into the neckband 13 (in the neck) in an arc shape. And pressed against the back of the user's neck.

  Here, the support member 16 has a larger amount of protrusion as the distance between the both ends connected to the neckband 13 (distance between the connection points) becomes smaller (as both ends of the neckband 13 get closer to each other). Therefore, as shown in FIG. 1A, when the neck of the user is thin, the neck band 13 is closed, and the distance between both ends of the support member 16 (distance between connection points) is reduced. The amount of protrusion to the cervical side increases. On the other hand, as shown in FIG. 1B, when the user's neck is thick, the neckband 13 opens to the left and right, and the distance between both ends of the support member 16 (distance between connection points) is It becomes larger and the amount of protrusion to the neck side becomes smaller.

  Therefore, regardless of the thickness of the user's neck (neck), the support member 16 can be brought into contact with the back of the user's neck, and the blood pressure fluctuation estimation device 3 (the neckband 13 and the support member 16) can be used. Can be mounted stably. In particular, at the time of wearing, the neck band 13 is closed according to the thickness of the neck of the user and the support member 16 is pushed out in the neck direction, so that both (left and right) ends of the neck band 13 and the support member 16 The neck can be stably held at three locations (three points).

  Sensor portions (contact portions) 11 and 12 are attached to the inner side surfaces of both ends of the neckband 13. A photoelectric pulse wave sensor 20 is attached to the inner surface of the support member 16. Here, the sensor parts 11 and 12 are centered on the short direction and / or the longitudinal direction of the neckband 13 (or the axial direction of the user's neck and / or the longitudinal direction of the neck perpendicular to the axial direction). It is preferably attached so as to be able to swing. More specifically, for example, each of the sensor units 11 and 12 is connected to both ends of the neckband 13 by a ball joint (not shown) having a spherical head and a socket for holding the spherical head. It is attached to the part so as to be swingable and rotatable.

  Therefore, each of the sensor portions 11 and 12 can swing about the short direction of the neckband 13 (that is, swingable in the circumferential direction of the neck), and at the same time, swings about the longitudinal direction of the neckband 13. It can move (that is, it can swing in the axial direction of the neck). Each of the sensor units 11 and 12 only needs to be able to swing around the short side and the long side of the neckband 13 and is provided with a mechanism that restricts (regulates) rotation about the radial direction of the neck. May be. Similarly, the photoelectric pulse wave sensor 20 may be attached so as to be swingable about the short side direction and / or the long side direction of the neckband 13.

  Inside the neckband 13 (rubber coating) and the support member 16, the sensor units 11 and 12 (electrocardiographic electrodes 15 and 15 to be described later), the photoelectric pulse wave sensor 20, the acceleration sensor 22 and the signal processing unit 31 are electrically connected. The cable to be connected to is wired. Here, it is desirable that the cable be coaxial in order to reduce noise.

  The sensor units 11 and 12 have a pair of electrocardiographic electrodes 15 and 15. Examples of the electrocardiographic electrode 15 include silver / silver chloride, conductive gel, conductive rubber, conductive plastic, metal (preferably resistant to corrosion such as stainless steel and Au), conductive cloth, and metal surface with an insulating layer. Capacitive coupling electrodes coated with can be used. Here, as the conductive cloth, for example, a woven fabric, a knitted fabric or a non-woven fabric made of conductive yarn having conductivity is used. In addition, as the conductive yarn, for example, a resin yarn whose surface is plated with Ag, a carbon nanotube-coated one, or a conductive polymer such as PEDOT is used. Moreover, you may use the conductive polymer thread | yarn which has electroconductivity. In the present embodiment, a conductive cloth 15 formed in a rectangular planar shape is used as the electrocardiographic electrode 15. Each of the pair of electrocardiographic electrodes 15, 15 is connected to the signal processing unit 31 and outputs an electrocardiographic signal to the signal processing unit 31.

  The support member 16 is attached with an acceleration sensor 22 that detects the posture of the user (neck) when acquiring the pulse wave propagation time. The acceleration sensor 22 is a three-axis acceleration sensor that detects the direction in which the gravitational acceleration G is applied (that is, the vertical direction), and determines, for example, whether the user is standing or sleeping from the detection signal. be able to.

  More specifically, the positional relationship of the acceleration sensor 22 with respect to the user's body is calibrated in advance, for example, when the user stands with respect to the output of the acceleration sensor 22 The user's posture can be determined by performing coordinate conversion with the direction in which gravity acceleration is applied as the downward direction (vertical direction). The acceleration sensor 22 is also connected to the signal processing unit 31 and outputs a detection signal (three-axis acceleration data) to the signal processing unit 31. Instead of the acceleration sensor 22, for example, a gyro sensor or the like can be used.

  A photoelectric pulse wave sensor 20 that has a light emitting element 201 and a light receiving element 202 in the vicinity of the acceleration sensor 22 and detects a photoelectric pulse wave signal is disposed on the inner surface of the support member 16 (the surface that contacts the neck). ing. The photoelectric pulse wave sensor 20 is a sensor that optically detects a photoelectric pulse wave signal using the light absorption characteristic of blood hemoglobin.

  As described above, the photoelectric pulse wave sensor 20 is disposed at a substantially central portion of the support member 16. Therefore, when the neckband 13 is worn on the neck of the user (that is, when the pulse wave propagation time is acquired), the photoelectric pulse wave sensor 20 has a midline ( (Or the vicinity thereof) at a position in contact with the neck. The photoelectric pulse wave sensor 20 is formed so that the surface thereof is the same (or substantially the same) as the surface of the support member 16.

  The photoelectric pulse wave sensor 20 and the acceleration sensor 22 are disposed close to each other, and are attached to the neck (neck) of the user when in use (measurement). In this way, by attaching the photoelectric pulse wave sensor 20 and the acceleration sensor 22 for determining the posture to the same part, the correlation between the posture determination and the pulse wave propagation time can be enhanced. In addition, by attaching to the cervix instead of the limbs, it is possible to estimate the intravascular blood pressure of the cervix, which is presumed to be highly correlated with the risk of stroke, myocardial infarction, etc., rather than the intravascular blood pressure of the limb. Further, by concentrating a plurality of sensors on the neck instead of being attached to different parts, it is possible to reduce the complexity of wearing and to reduce the restrictions on daily activities. The acceleration sensor 22 is desirably disposed in the vicinity of the photoelectric pulse wave sensor 20, but may be disposed at other locations in the apparatus as long as the relative position with respect to the photoelectric pulse wave sensor 20 does not vary. Good.

  The light emitting element 201 emits light according to a pulsed drive signal output from the drive unit 350 of the signal processing unit 31 described later. As the light emitting element 201, for example, an LED, a VCSEL (Vertical Cavity Surface Emitting LASER), or a resonator type LED can be used. Note that the driving unit 350 generates and outputs a pulsed driving signal for driving the light emitting element 201.

  The light receiving element 202 outputs a detection signal corresponding to the intensity of light irradiated from the light emitting element 201 and transmitted through the neck or reflected from the neck. As the light receiving element 202, for example, a photodiode or a phototransistor is preferably used. In the present embodiment, a photodiode is used as the light receiving element 202.

  The light receiving element 202 is connected to the signal processing unit 31, and a detection signal (photoelectric pulse wave signal) obtained by the light receiving element 202 is output to the signal processing unit 31.

  In addition, a battery (not shown) that supplies electric power to the photoelectric pulse wave sensor 20, the signal processing unit 31, the wireless communication module 60, and the like is housed inside the sensor unit 11. Inside the sensor unit 12, there is a signal processing unit 31 and a wireless communication module 60 that transmits biological information such as blood pressure fluctuation, measured pulse wave propagation time, electrocardiogram signal, and photoelectric pulse wave signal to an external device. It is stored.

  As described above, each of the pair of electrocardiographic electrodes 15 and 15 and the photoelectric pulse wave sensor 20 is connected to the signal processing unit 31, and the detected electrocardiogram signal and photoelectric pulse wave signal are transmitted to the signal processing unit 31. Entered. The acceleration sensor 22 is also connected to the signal processing unit 31, and the detected triaxial acceleration signal is input to the signal processing unit 31.

  The signal processing unit 31 processes the input electrocardiogram signal and measures a heart rate, a heart beat interval, and the like. In addition, the signal processing unit 31 processes the input photoelectric pulse wave signal and measures the pulse rate, the pulse interval, and the like. Further, the signal processing unit 31 measures the pulse wave propagation time and the like from the time difference between the R wave peak of the detected electrocardiogram signal (cardiac radio wave) and the peak (rising point) of the photoelectric pulse wave signal (or acceleration pulse wave signal). To do. And the signal processing part 31 estimates the fluctuation | variation of a user's blood pressure from the time series data (fluctuation) of the measured pulse wave propagation time.

  Therefore, the signal processing unit 31 includes an electrocardiogram signal amplification unit 311, a pulse wave signal amplification unit 321, a first signal processing unit 310, a second signal processing unit 320, peak detection units 316 and 326, peak correction units 318 and 328, It has a pulse wave propagation time measurement unit 330, a posture classification unit 340, a pulse wave propagation time variation acquisition unit 341, and a blood pressure variation estimation unit 342. The first signal processing unit 310 includes an analog filter 312, an A / D converter 313, and a digital filter 314. On the other hand, the second signal processing unit 320 includes an analog filter 322, an A / D converter 323, a digital filter 324, and a second-order differentiation processing unit 325.

  Here, among the above-described units, the digital filters 314, 324, the second-order differentiation processing unit 325, the peak detection units 316, 326, the peak correction units 318, 328, the pulse wave propagation time measurement unit 330, the posture classification unit 340, the pulse The wave propagation time fluctuation acquisition unit 341 and the blood pressure fluctuation estimation unit 342 temporarily store various data such as a CPU that performs arithmetic processing, a ROM that stores programs and data for causing the CPU to execute each processing, and arithmetic results. It is comprised by RAM etc. which memorize | store in. That is, the functions of the above-described units are realized by executing the program stored in the ROM by the CPU.

  The electrocardiogram signal amplifying unit 311 is constituted by an amplifier using, for example, an operational amplifier, and amplifies the electrocardiogram signals detected by the pair of electrocardiographic electrodes (conductive cloth) 15 and 15. The electrocardiographic signal amplified by the electrocardiographic signal amplification unit 311 is output to the first signal processing unit 310. Similarly, the pulse wave signal amplifying unit 321 is configured by an amplifier using, for example, an operational amplifier, and amplifies the photoelectric pulse wave signal detected by the photoelectric pulse wave sensor 20. The photoelectric pulse wave signal amplified by the pulse wave signal amplification unit 321 is output to the second signal processing unit 320.

  As described above, the first signal processing unit 310 includes the analog filter 312, the A / D converter 313, and the digital filter 314, and filters the electrocardiogram signal amplified by the electrocardiogram signal amplification unit 311. The pulsation component is extracted by processing.

  Further, as described above, the second signal processing unit 320 includes the analog filter 322, the A / D converter 323, the digital filter 324, and the second-order differentiation processing unit 325, and is amplified by the pulse wave signal amplification unit 321. The pulsating component is extracted by subjecting the photoelectric pulse wave signal to filtering processing and second-order differentiation processing.

  The analog filters 312, 322 and the digital filters 314, 324 remove components (noise) other than the frequency characterizing the electrocardiogram signal and the photoelectric pulse wave signal, and perform filtering for improving the S / N. More specifically, the ECG signal is generally dominated by a frequency component of 0.1 to 200 Hz, and the photoelectric pulse wave signal is dominated by a frequency component of 0.1 to several tens of Hz. The S / N is improved by performing filtering using the analog filters 312 and 322 and the digital filters 314 and 324 and selectively passing only signals in the frequency range.

  In the case where only the extraction of the pulsating component is intended, in order to improve noise resistance, the pass frequency range may be narrowed to block components other than the pulsating component. The analog filters 312, 322 and the digital filters 314, 324 are not necessarily provided, and only one of the analog filters 312, 322 and the digital filters 314, 324 may be provided. Note that the electrocardiogram signal subjected to the filtering process by the analog filter 312 and the digital filter 314 is output to the peak detection unit 316. Similarly, the photoelectric pulse wave signal subjected to the filtering process by the analog filter 322 and the digital filter 324 is output to the second-order differentiation processing unit 325.

  The second-order differentiation processing unit 325 obtains a second-order differential pulse wave (acceleration pulse wave) signal by performing second-order differentiation on the photoelectric pulse wave signal. The acquired acceleration pulse wave signal is output to the peak detector 326. The peak (rising point) of the photoelectric pulse wave is not clearly changed and may be difficult to detect. Therefore, it is preferable to detect the peak by converting it to an acceleration pulse wave. However, a second-order differential processing unit 325 is provided. Is not essential and may be omitted.

  The peak detection unit 316 detects the peak (R wave) of the electrocardiogram signal that has been subjected to signal processing by the first signal processing unit 310 (the pulsating component has been extracted). On the other hand, the peak detection unit 326 detects the peak of the photoelectric pulse wave signal (acceleration pulse wave) subjected to the filtering process by the second signal processing unit 320. Each of the peak detection unit 316 and the peak detection unit 326 performs peak detection within the normal range of the heartbeat interval and the pulse interval, and information on the peak time, peak amplitude, and the like for all detected peaks is stored in the RAM or the like. save.

  The peak correction unit 318 obtains the delay time of the electrocardiographic signal in the first signal processing unit 310 (analog filter 312, A / D converter 313, digital filter 314). The peak correction unit 318 corrects the peak of the electrocardiogram signal detected by the peak detection unit 316 based on the obtained delay time of the electrocardiogram signal. Similarly, the peak correction unit 328 obtains the delay time of the photoelectric pulse wave signal in the second signal processing unit 320 (analog filter 322, A / D converter 323, digital filter 324, second-order differentiation processing unit 325). The peak correction unit 328 corrects the peak of the photoelectric pulse wave signal (acceleration pulse wave signal) detected by the peak detection unit 326 based on the obtained delay time of the photoelectric pulse wave signal. The corrected peak of the electrocardiogram signal and the corrected peak of the photoelectric pulse wave signal (acceleration pulse wave) are output to the pulse wave propagation time measurement unit 330. Note that providing the peak correction unit 318 is not essential and may be omitted.

  The pulse wave propagation time measurement unit 330 is configured to detect an interval (time difference) between the R wave peak of the electrocardiogram signal corrected by the peak correction unit 318 and the peak of the photoelectric pulse wave signal (acceleration pulse wave) corrected by the peak correction unit 328. ) To obtain the pulse wave propagation time in time series.

  In addition to the pulse wave propagation time, the pulse wave propagation time measurement unit 330 calculates, for example, a heart rate, a heart beat interval, a heart beat interval change rate, and the like from an electrocardiogram signal. Similarly, the pulse wave propagation time measurement unit 330 calculates a pulse rate, a pulse interval, a pulse interval change rate, and the like from the photoelectric pulse wave signal (acceleration pulse wave). The acquired time-series data of the pulse wave propagation time is output to the attitude classification unit 340.

  The posture classification unit 340 determines (estimates) the posture of the user based on the detection signal (three-axis acceleration data) of the acceleration sensor 22, and uses the time-series data of the pulse wave propagation time according to the determined posture. Sort by each. For example, the posture classification unit 340 classifies the time-series data of the pulse wave propagation time for each posture including a standing position, an inverted position, a supine position, a left side position, a right side position, and a prone position. Note that the classification result of the pulse wave propagation time by the posture classification unit 340 (the time series data of the classified pulse wave propagation time) is output to the pulse wave propagation time fluctuation acquisition unit 341.

  The pulse wave propagation time fluctuation acquisition unit 341 obtains the fluctuation of the pulse wave propagation time based on the time series data of the pulse wave propagation time classified for each posture by the posture classification unit 340.

  More specifically, the pulse wave transit time fluctuation acquisition unit 341 first sets a reference posture from among the classified postures, and is classified into a posture different from the reference posture according to the reference posture. Correct time-series data of pulse wave propagation time. The pulse wave propagation time variation acquisition unit 341 then calculates the pulse wave propagation time based on the time series data of the pulse wave propagation time in the reference posture and the corrected (corrected) time series data of the pulse wave propagation time. Find the fluctuations.

  At that time, the pulse wave propagation time variation acquisition unit 341 sets the posture with the longest time-series data of the acquired pulse wave propagation time as the reference posture. The pulse wave propagation time variation acquisition unit 341 then increases the correlation coefficient of the approximate curve when the time series data of the pulse wave propagation time for each posture is approximated by a curve (preferably maximizes). Then, the time series data of the pulse wave propagation time for each posture is corrected, and the fluctuation of the pulse wave propagation time is obtained from the corrected time series data. In this way, by correcting the pulse wave propagation time for each posture so that the correlation coefficient of the approximate curve becomes large, and estimating the fluctuation tendency of the pulse wave propagation time from the corrected time series data, the posture change is Even in some cases, a long-term pulse wave transit time fluctuation tendency (blood pressure fluctuation tendency) can be estimated without complicated calibration. In addition, as a method of obtaining the approximate curve, for example, a least square method can be used.

  Instead of the method described above, the pulse wave propagation times for each posture may be arranged in time series, and approximate curves may be obtained for each. In this case, although a plurality of approximate curves are calculated, an approximate curve having a large correlation coefficient is selected from the approximate curves having a posture of a predetermined time ratio or more. The fluctuation data of the pulse wave propagation time acquired by the pulse wave propagation time fluctuation acquisition unit 341 is output to the blood pressure fluctuation estimation unit 342.

  The blood pressure fluctuation estimation unit 342 estimates blood pressure fluctuations based on the fluctuation data of the corrected pulse wave propagation time and a predetermined relationship (correlation formula) between the pulse wave propagation time and the blood pressure. Here, the blood pressure fluctuation estimation unit 342 estimates the blood pressure fluctuation from, for example, a correlation expression between the pulse wave propagation time and the blood pressure in a reference posture that has been obtained in advance, so that the blood pressure fluctuation is calculated from the corrected pulse wave propagation time fluctuation. Variations can be estimated.

  The blood pressure fluctuation estimation unit 342 performs calibration for posture determination in a worn state in advance, that is, calibration of the relationship between the output signal (vertical direction) of the acceleration sensor 22 and the posture of the user. Then, a relational expression between the angle deviation from the reference posture (shift angle) and the height from the heart to the pulse wave measurement site (that is, the site where the photoelectric pulse wave sensor 20 is mounted) is obtained and stored in a memory such as a RAM. When the pulse wave propagation time is measured (during use), the angle deviation between the user's posture detected by the acceleration sensor 22 and the reference posture based on the result of calibration performed in advance (deviation) When calculating the blood pressure value from the pulse wave propagation time, the pulse wave measurement unit from the heart is calculated based on the calculated angle deviation (shift angle) and the relational expression stored in advance. Seeking to height (mounting portion of the photoelectric pulse wave sensor 20), it may be corrected blood pressure value according to the height. However, the blood pressure value does not necessarily have to be obtained.

  Measurement data such as estimated blood pressure fluctuation, blood pressure value, calculated pulse wave propagation time, heart rate, heart rate interval, pulse rate, pulse interval, photoelectric pulse wave, acceleration pulse wave, triaxial acceleration, etc. are stored in RAM, etc. To the memory, the wireless communication module 60, and the like. Here, these measurement data may be stored in a memory and read together with daily fluctuation history, or transmitted in real time to an external device such as a personal computer (PC) or a smartphone. You may do it. Further, it may be configured so that it is stored in a memory in the apparatus during measurement, and is automatically connected to an external device after transmission and data is transmitted.

  Next, the operation of the blood pressure fluctuation estimation device 3 will be described with reference to FIG. FIG. 4 is a flowchart showing a processing procedure of blood pressure fluctuation estimation processing by the blood pressure fluctuation estimation device 3. The processing shown in FIG. 4 is repeatedly executed mainly at a predetermined timing by the signal processing unit 31.

  The blood pressure fluctuation estimation device 3 is attached to the neck, the sensor units 11 and 12 (electrocardiographic electrodes 15 and 15) are in contact with the left and right sides of the neck, the support member 16 protrudes, and the photoelectric pulse wave sensor 20 is connected to the neck. When the rear midline (or the vicinity thereof) is contacted, in step S100, the electrocardiogram signals detected by the pair of electrocardiogram electrodes 15 and 15 and the photoelectric pulse wave signal detected by the photoelectric pulse wave sensor 20 are read. It is. In subsequent step S102, filtering processing is performed on the electrocardiogram signal and photoelectric pulse wave signal read in step S100. Further, the acceleration pulse wave is obtained by second-order differentiation of the photoelectric pulse wave signal.

  Subsequently, in step S104, for example, the mounting state of the pulse wave transit time measuring device 1 is determined based on the amount of light received by the photoelectric pulse wave sensor 20. That is, the photoelectric pulse wave sensor 20 receives the light irradiated from the light emitting element 201, transmitted through the living body / reflected by the living body, and returned by the light receiving element 202, and detects the fluctuation of the light amount as a photoelectric pulse wave signal. Therefore, the amount of received signal light decreases when the device is not properly mounted. Therefore, in step S104, a determination is made as to whether the amount of received light is equal to or greater than a predetermined value. If the received light amount is greater than or equal to the predetermined value, the process proceeds to step S108. On the other hand, when the amount of received light is less than the predetermined value, it is determined as a mounting error, and mounting error information (warning information) is output in step S106. Thereafter, the process is temporarily exited. In place of the method using the received light amount of the photoelectric pulse wave sensor 20 described above, for example, a method using the amplitude of the photoelectric pulse wave signal, the baseline stability of the electrocardiogram waveform, the noise frequency component ratio, or the like is adopted. You can also.

  In step S108, a determination is made as to whether or not the neck acceleration detected by the acceleration sensor 22 is equal to or greater than a predetermined threshold (that is, whether or not the neck moves and body motion noise increases). Is called. If the neck acceleration is less than the predetermined threshold value, the process proceeds to step S112. On the other hand, when the acceleration of the neck is equal to or greater than the predetermined threshold value, the body movement error information is output in step S110, and then the process is temporarily exited.

  In step S112, the posture of the user (measurement site) is determined based on the triaxial acceleration data. In the subsequent step S114, the peaks of the electrocardiogram signal and the photoelectric pulse wave signal (acceleration pulse wave signal) are detected. Then, the time difference (peak time difference) between the R wave peak of the detected electrocardiogram signal and the peak of the photoelectric pulse wave signal (acceleration pulse wave) is calculated.

  Next, in step S116, the delay time (shift amount) of each of the R wave peak of the electrocardiogram signal and the peak of the photoelectric pulse wave signal (acceleration pulse wave) is obtained, and based on the obtained delay time, the electrocardiogram is obtained. The time difference (peak time difference) between the R wave peak of the signal and the peak of the photoelectric pulse wave signal (acceleration pulse wave) is corrected.

  Subsequently, in step S118, a determination is made as to whether or not the peak time difference corrected in step S116 is greater than or equal to a predetermined time (for example, 0.01 sec.). If the peak time difference is greater than or equal to the predetermined time, the process proceeds to step S122. On the other hand, when the peak time difference is less than the predetermined value, error information (noise determination) is output in step S120, and then the process is temporarily exited.

  In step S122, the peak time difference calculated in step S114 is determined as the pulse wave propagation time, and the pulse wave interval is acquired.

  Subsequently, in step S124, the pulse wave propagation time is classified for each posture of the user. Since the pulse wave propagation time classification method is as described above, detailed description is omitted here.

  Next, in step S126, the pulse wave propagation time is corrected so that the correlation coefficient of the approximate curve becomes the largest. Since the pulse wave propagation time correction method is as described above, detailed description thereof is omitted here.

  Subsequently, in step S128, the blood pressure fluctuation is estimated from the fluctuation of the corrected pulse wave propagation time. Since the blood pressure fluctuation estimation method is as described above, detailed description thereof is omitted here. In step S130, the acquired blood pressure fluctuation data or the like is output to an external device such as a memory or a smartphone. Thereafter, the process is temporarily exited.

  As described above in detail, according to the present embodiment, the neckband 13 is formed in a substantially C shape and has elasticity so that both end portions approach each other (the width of the opening portion becomes narrower). To be energized. That is, it is urged in the direction of clamping the user's neck at the time of wearing. Further, as the support member 16 approaches the both ends of the neckband 13 by the urging force of the neckband 13 (that is, the neck of the user is thinner and the opening degree is smaller), the inner side of the neckband 13 ( When worn, it is deformed and protrudes (extruded) toward the neck. Therefore, the inner diameter of the neckband 13 and the protruding amount of the support member 16 are automatically (autonomously) adjusted according to the thickness of the neck of the user. As a result, without having a mechanism for adjusting the length of the neckband 13, it is more stably worn by the user's neck regardless of the thickness of the user's neck (ie, in contact with the neck) Can be kept good).

  In particular, according to the present embodiment, the support member 16 has flexibility (or elasticity), and the distance between the two ends connected to the neckband 13 (between connection points) by the urging force of the neckband 13. As the distance becomes shorter (both ends of the neckband 13 are closer to each other), it is pushed out in an arc shape inside the neckband 13 (in the neck direction when worn) by elastic deformation. Therefore, a simpler, smaller and lighter mechanism can be stably attached to users with different neck thicknesses.

  According to the present embodiment, the sensor units 11 and 12 are attached so as to be swingable about the short side direction and / or the long side direction of the neckband 13. As described above, the sensor units 11 and 12 are attached so as to be swingable around the short direction of the neckband 13 (that is, swingable in the circumferential direction of the neck portion). Even if the thicknesses of the parts differ, the sensor parts 11 and 12 can be brought into close contact with the user's neck. In addition, for example, the contact surface can be held following a movement in which the neck is twisted. As a result, it is possible to maintain good contact with the neck regardless of individual differences such as the thickness of the neck and the movement of the neck. Further, in this case, since the sensor parts 11 and 12 are attached so as to be able to swing around the longitudinal direction of the neckband 13 (that is, swingable in the axial direction of the neck part), It is possible to hold the contact surface following the movement of the part being inclined.

  According to the present embodiment, the sensor units 11 and 12 are disposed on the inner side surface of the neckband 13, and the photoelectric pulse wave sensor 20 is in contact with the inner side surface of the support member 16 (that is, the side that contacts the neck side surface when worn). On the surface). Therefore, even if the thickness of the neck of the user is different, the sensor units 11 and 12 and the photoelectric pulse wave sensor 20 can be stably brought into contact with the neck, and biological signals can be detected (measured) stably. ).

(Second Embodiment)
Next, the biosignal detection device 2 according to the second embodiment will be described with reference to FIG. Here, the description of the same or similar configuration as in the first embodiment will be simplified or omitted, and different points will be mainly described. FIG. 5 is a plan view showing the external shape of a neckband blood pressure fluctuation estimation device 4 using the biological signal detection device 2, wherein (a) shows the shape when worn on a thin neck, and (b) ) Is a diagram showing the shape when mounted on a thick neck. In FIG. 5, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals.

  The blood pressure fluctuation estimation apparatus 4 (biological signal detection apparatus 2) includes a support member 17 instead of the support member 16, and thus the blood pressure fluctuation estimation apparatus 3 (biological signal detection apparatus 1) according to the first embodiment described above. ) Is different. Other configurations are the same as or similar to those of the blood pressure fluctuation estimation device 3 (biological signal detection device 1) described above, and thus detailed description thereof is omitted here.

  The support member 17 includes a plurality (three in this embodiment) of connecting members (joints), that is, the first connecting member 17a, the second connecting member 17b, and the third connecting member 17c can swing (bend). Are connected to each other. Each connecting member 17a, 17b, 17c is connected to be relatively swingable by, for example, a hinge or the like. Each hinge (connecting portion) may be provided with an elastic member such as a spring for urging the second connecting member 17b toward the inside of the neckband 13 (in the neck portion direction when worn).

  For this reason, the support member 17 has a shorter distance between both ends connected to the neckband 13 (a distance between connection points) due to the urging force of the neckband 13 (that is, the closer both ends of the neckband 13 are to each other). ) Swings (bends) so that the angle formed between the neckband 13 and the neckband 13 is large, protrudes (extrusion) to the inside (neck direction) of the neckband 13, and the user's neck Pushed backwards.

  Here, the support member 17 (second connecting member 17b) is such that the distance between the two ends connected to the neckband 13 (the distance between the connection points) is smaller (the two ends of the neckband 13 are closer to each other). , The amount of protrusion increases. Therefore, as shown in FIG. 5A, when the neck of the user is thin, the neck band 13 is closed, and the distance between both ends of the support member 17 (distance between connection points) is reduced. The amount of protrusion to the cervical side increases. On the other hand, as shown in FIG. 5B, when the user's neck is thick, the neckband 13 opens to the left and right, and the distance between both ends of the support member 17 (distance between connection points) is It becomes larger and the amount of protrusion to the neck side becomes smaller.

  Therefore, regardless of the thickness of the user's neck (neck), the support member 17 can be brought into contact with the back of the user's neck, and the blood pressure fluctuation estimation device 4 (the neckband 13 and the support member 17) can be used. Can be mounted stably. In particular, at the time of wearing, the neck band 13 is closed according to the thickness of the neck of the user, and the support member 17 (second connecting member 17b) is pushed out in the neck direction. The neck can be stably held at three positions (three points) of the end and the support member 17 (second connecting member 17b).

  A photoelectric pulse wave sensor 20 is disposed on the second connecting member 17b. Since the photoelectric pulse wave sensor 20 is as described above, detailed description thereof is omitted here. Other configurations are the same as or similar to those of the support member 16 described above, and detailed description thereof is omitted here.

  The blood pressure fluctuation estimation device 4 (biological signal detection device 2) can be used in the same manner as the blood pressure fluctuation estimation device 3 (biological signal detection device 1) described above. That is, the user detects and measures an electrocardiogram signal, a photoelectric pulse wave signal, a pulse wave propagation time, a blood pressure fluctuation, and the like only by wearing the blood pressure fluctuation estimation device 4 (biological signal detection device 2) on the neck. be able to. In addition, since the usage method of the blood pressure fluctuation estimation apparatus 3 (biological signal detection apparatus 1) is as above-mentioned, detailed description is abbreviate | omitted here.

  According to the present embodiment, the support member 17 has the three connecting members (joints) 17 a, 17 b, and 17 c that are swingably (flexible) connected to each other, and the neckband 13 is biased by the urging force of the neckband 13. 13, the shorter the distance between both ends connected to 13 (the distance between the connection points) (the closer both ends of the neckband 13 are to each other), the closer the neckband 13 to the support member 17 (the connecting members 17a and 17c). It swings (bends) so as to increase the angle formed, and protrudes (pushes out) to the inside of the neckband 13 (in the neck direction when worn). Therefore, a relatively simple, small, and lightweight mechanism can be stably attached to users with different neck thicknesses.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above embodiment, the case where the biological signal detection device 1 (2) is applied to the blood pressure fluctuation estimation device 3 (4) has been described as an example, but the biological signal detection device 1 (2) is a blood pressure fluctuation estimation device 3. It can be applied to other than (4).

  In the above embodiment, the biological signal detection device 1 (2) includes the photoelectric pulse wave sensor 20, but may be configured not to include the photoelectric pulse wave sensor 20. As the pulse wave sensor, for example, a piezoelectric pulse wave sensor may be used instead of the photoelectric pulse wave sensor. Furthermore, in the above embodiment, one photoelectric pulse wave sensor 20 is disposed on the support member 16 (17). However, a plurality of biological sensors may be disposed in addition to or instead of the photoelectric pulse wave sensor 20. Good. In addition to the various sensors described above, for example, a biosensor such as an oxygen saturation sensor, a sound sensor (microphone), a displacement sensor, a temperature sensor, and a humidity sensor may be used. Further, although the sensor units 11 and 12 have a pair of electrocardiographic electrodes 15 and 15, a photoelectric pulse wave sensor, a piezoelectric pulse wave sensor, an oxygen saturation sensor, a sound sensor (microphone), a displacement sensor, You may arrange | position biological sensors, such as a temperature sensor and a humidity sensor.

  In the above embodiment, the sensor parts 11 and 12 are attached to both ends of the neckband 13, but the sensor parts 11 and 12 are not necessarily attached to both ends of the neckband 13.

  In the above-described embodiment, processing such as posture determination, correction of pulse wave propagation time for each posture, estimation of blood pressure fluctuation, etc. was performed by the signal processing unit 31, but the acquired electrocardiogram signal, photoelectric pulse wave signal, triaxial acceleration For example, wirelessly outputting data such as a personal computer (PC) or a smartphone, and performing processing such as posture determination, correction of pulse wave propagation time for each posture, estimation of blood pressure fluctuation, etc. on the PC or smartphone side It is good. In such a case, data such as the correlation equation described above is stored on the PC or smartphone side.

DESCRIPTION OF SYMBOLS 1, 2 Biosignal detection apparatus 3, 4 Blood pressure fluctuation estimation apparatus 11, 12 Sensor part 13 Neckband 15 Electrocardiogram electrode 16, 17 Support member 17a, 17b, 17c Connection member 20 Photoelectric pulse wave sensor 201 Light emitting element 202 Light receiving element 22 Acceleration sensor 31 Signal processing unit 310 First signal processing unit 320 Second signal processing unit 311 ECG signal amplification unit 321 Pulse wave signal amplification unit 312, 322 Analog filter 313, 323 A / D converter 314, 324 Digital filter 325 Second floor Differential processing unit 316, 326 Peak detection unit 318, 328 Peak correction unit 330 Pulse wave propagation time measurement unit 340 Posture classification unit 341 Pulse wave propagation time variation acquisition unit 342 Blood pressure variation estimation unit 60 Wireless communication module

Claims (6)

A neckband that can be worn along the circumferential direction of the user's neck;
A sensor unit that is attached to the neckband and detects a biological signal;
A support member having both ends connected to the inner side surface of the neckband,
The neckband is formed in a substantially C shape, and is biased in a direction in which both ends approach each other,
The biological signal detection device according to claim 1, wherein the support member protrudes toward the inside of the neckband as the both end portions of the neckband approach each other due to the urging force of the neckband.   The support member has flexibility, and is deformed as the distance between both ends connected to the neckband becomes shorter due to the urging force of the neckband, so that the support member deforms in an arc shape to the inside of the neckband. The biological signal detection device according to claim 1, wherein the biological signal detection device protrudes.   The support member has a plurality of connecting members that are swingably connected to each other, and as the distance between both ends connected to the neckband becomes shorter due to the biasing force of the neckband, The biological signal detection device according to claim 1, wherein the biological signal detection device swings so as to increase an angle formed therebetween and protrudes to the inside of the neckband.   The said sensor part is attached so that rocking is possible centering on the axial direction of a user's neck at the time of mounting | wearing and / or the neck front-back direction perpendicular | vertical to this axial direction. The biological signal detection device according to any one of the above.   The biological signal detection device according to any one of claims 1 to 3, wherein the sensor unit is attached so as to be swingable about the short side direction and / or the long side direction of the neckband. . The biological signal detection device according to claim 1, wherein the sensor unit is disposed on an inner surface of the neckband and / or a support member.

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